1. Field of the Invention
The present invention relates to a method, program product, and game system for blurring an image. More particularly, the present invention relates to a method of blurred drawing processing for three-dimensional computer image processing and a computer readable program product storing a program and video game system for the same.
2. Description of the Related Art
In image processing for three-dimensional computer games used by video game systems, processing the image so as to give the image drawn in the virtual three-dimensional space of the monitor screen a blurred effect like that according to the depth of an object etc. and drawing the image in a non-focused state has already been proposed. This type of image processing technique is disclosed in Japanese Unexamined Patent Publication (Kokai) No. 6-139353, Japanese Unexamined Patent Publication (Kokai) No. 10-222694, etc.
Summarizing the problems to be solved by the invention, blurred drawing processing gradually increases the blurring degree the further toward the deep side of the virtual three-dimensional space such as with the effect of a depth of field in an image taken by a camera and gives a naturally appearing non-focused image. While it is possible to change the blurring degree given in the depth direction of the virtual three-dimensional space step by step, the greater the number of steps of the blurring degree, the larger the load in the blurring drawing processing and the more high speed drawing is obstructed.
If therefore reducing the number of steps of the blurring degree given in the depth direction of the virtual three-dimensional space, the difference in the blurring effect in the interface area between an image of a large blurring degree and an image of a small degree becomes uniformly large and therefore an unnaturally appearing image of a virtual three-dimensional space is displayed.
In particular, in a fighting game where an enemy character designed to fight with the player character moves between a front side and deep side of the virtual three-dimensional space, when the enemy character moves between the front side and deep side of the virtual three-dimensional space, the displayed image (blurring degree) of the enemy character changes by an extreme amount and appears unnatural. For example, when the enemy character moves from the deep side to the front side in the virtual three-dimensional space, the blurred displayed image of the enemy character abruptly changes to a highly focused image. There is an unnatural change in scene where it appears that the enemy character breaks through a curtain of fog.
An object of the present invention is to provide a method of blurred drawing processing, and a computer readable program product storing a program for three-dimensional computer image processing and a video game system for the same, enabling the display of a virtual three-dimensional space on a screen having the effect of a depth of field free from an unnatural feeling without increasing the load of the blurred drawing processing, that is, without increasing the number of steps of blurring degree given in the depth direction of the virtual three-dimensional space.
According to a first aspect of the present invention, there is provided a method for blurring a scene of a game, the method including setting a depth from any perspective point for a scene in a virtual space, setting a blurring degree higher the deeper the set depth, executing blurring processing on said scene based on the set blurring degree, and displaying the scene obtained by the executed blurring processing.
According to a second aspect of the present invention, there is provided a computer readable program product storing a game program, the program making the computer set a depth from any perspective point for a scene in a virtual space, set a blurring degree higher the deeper the set depth, executing blurring processing based on said set blurring degree to said scene, and displaying the scene obtained by said executed blurring processing.
According to a third aspect of the present invention, there is provided a game system provided with a unit for playing a game in accordance with a program, a memory for storing all or part of the program, and a display screen for displaying a game played by the unit, the unit, in accordance with the program stored in the memory, setting a depth from any perspective point for a scene in a virtual space, setting a blurring degree higher the deeper the set depth, executing blurring processing on said scene based on the set blurring degree, and displaying the scene obtained by the executed blurring processing.